An objective measurement tool defined in the ITU-T Recommendation P.862 for the evaluation of transmission quality. PESQ is an automated measurement tool that addresses the effects of filters, jitter, and coding distortions. PESQ is analogous to the mean opinion score (MOS) defined in P.800, which is a much more subjective approach involving a panel of human listeners. See also ITU-T, P.800, P.862, and toll quality.